An SQL View in GeoServer is a feature that turns a database query into a published map layer. Instead of exposing a whole table, administrators define a query that selects, joins, filters, or reshapes data, and GeoServer serves the result through its web services. This is useful for geospatial publishing because it can simplify complex datasets and expose only the fields or rows that a client needs.
SQL Views matter in security because they place SQL directly in the request path. If user input is not tightly controlled, an attacker may alter the query and trigger SQL injection, leading to data leakage, unauthorized database actions, or, in some environments, a path toward broader system compromise. Defenses include parameterized query construction, allow-list validation for variables, least-privilege database accounts, and careful review of any feature that accepts external values before building SQL. In practice, SQL Views should be treated as sensitive application logic, not just a convenience feature.